Metrohm Raman Probes

Significance of the Topic

The performance and reliability of Raman probes are critical for accurate spectroscopic analysis across diverse industrial and research settings
Raman probes enable noninvasive, real-time monitoring of chemical composition in liquids, slurries, powders and solids under challenging temperature and pressure conditions
Advances in probe design, materials and optical interfaces directly impact signal quality, measurement depth and operational robustness

Aims and Overview of the Study

This document surveys the range of Raman probe and accessory options offered by B&W Tek for portable Raman systems
It categorizes probe configurations by excitation wavelength, material construction, mechanical and optical specifications, and operating conditions
The goal is to guide selection of the optimal probe for specific applications such as process monitoring, quality control and materials identification

Used Methodology and Instrumentation

B&W Tek probes and accessories are organized into four main groups and characterized by temperature and pressure limits, materials, geometry and optical interface

• Raman Probes for Portable Systems
  • Models BAC101-SS and BAC101-HS with 532, 785 and 1064 nm excitation
  • 316 stainless steel or Hastelloy C-276 shafts, sapphire ball or flat windows, epoxy or gold seals
  • Temperature range up to 300 °C and pressure up to 6000 psi
• Industrial Immersion Probe Shafts
  • Low-cost shafts with fused silica or sapphire windows for basic immersible use (up to 200 °C, 14 psi)
  • High-pressure, high-temperature shafts for direct immersion (up to 300 °C, 6000 psi)
  • Hot-melt extrusion shafts compatible with Dynisco ports for polymer process monitoring
• Large Area Probes for i-Raman® Prime and PTRam
  • Models for 785 and 1064 nm excitation with 4 mm measurement area
  • Flat quartz windows, aluminum housing, 1.5 m or 5 m bifurcated fiber assemblies
  • Ideal for heterogeneous solids and see-through identification through barriers
• Zoom Lens Options
  • Adjustable working distance lenses (20–60 mm, 60–600 mm, 0.6–6 m)
  • Support VIS-NIR and NIR ranges, enabling stand-off Raman measurements through thick glass or at elevated pressure and temperature
  • RTS series lenses replace standard probe shafts for noncontact analysis

Main Results and Discussion

The catalogued probes demonstrate robust operation across a wide range of harsh conditions while preserving high Raman signal throughput
Material selection (stainless steel vs Hastelloy) aligns with chemical compatibility and temperature requirements, and lens sealing methods affect durability and optical clarity
Fiber configurations and window design deliver >OD6 Rayleigh rejection and support excitation wavelengths at 532, 785 or 1064 nm with minimal background
Large area probes and zoom lens combinations extend measurement capabilities to bulk heterogenous samples and remote or in-reactor monitoring

Benefits and Practical Applications

These Raman probes support in-line and at-line process control in pharmaceutical synthesis, polymer extrusion, petrochemical processing and food quality assessment
Key advantages include

• Noninvasive sampling without consumables
• High pressure and temperature tolerance for real-time monitoring
• Flexible fiber-optic coupling for portable or remote analysis
• Customizable shaft lengths and materials for specific reactor geometries

Future Trends and Opportunities

Integration of machine learning for automated spectral interpretation in process analytics
Development of even higher temperature and pressure probes using advanced ceramics or metal alloys
Miniaturization for microscale reaction monitoring and integration into microfluidic systems
Enhanced window coatings and fiber designs to extend lifetime in abrasive or corrosive media
Novel lens assemblies for longer stand-off distances and improved spatial resolution

Conclusion

B&W Tek’s portfolio of Raman probes and accessories provides comprehensive solutions for diverse analytical challenges
Their modular design, material options and optical performance enable reliable, high-quality Raman measurements in harsh environments
Selecting the appropriate probe configuration ensures optimal data quality, operational safety and process efficiency
These tools lay the groundwork for expanded adoption of Raman spectroscopy in advanced process analytical technology (PAT) and real-time quality assurance